Lubricating compositions



United States Patent 3,100,749 LUBREQATWG CUMPGSHTEQNS Eugene Wittner,Florissant, Mo, and ki ling Rczalslry,

This invention relates to improved hydrocarbon lubricants, andparticularly to mineral lubricating oil compositions which possess gooddetergency and corrosion or rust inhibiting properties.

It is known thatcertain high molecular weight non-ash i i forming:copolymers of vinylpyridinearid other polymerizable compounds such asacrylate esters, e.g. .copolymer of a vinylpyridine and a C1448 alkylmethacrylate, function as detergents when added in small amounts tolubrinent and the other is a long chain acrylate of a C1440 cants suchas mineral lubricating oils; l-lowever, c0

5 lubricating oils,'two dissimilar copolymers comprising (A) a copolymerof a vinylpyridine and a C1040 alkyl methacrylate having a molccularweight range of from 50,000 to 300,000, preferably between 100,000 to200,000, and

a nitrogen content of from 2.5% to 3.5% and. (B), acopolymer of (1) avinylpyridine and, (.2) a mixtureof at least two dissimilar esters of anacrylic acid and two difterent aliphatic alcohols" one of which is a (3alkanol and the other alcoholis a C alkanoLthe acrylate of the C alkanolmaking up not more than 60% of the mixture (B) and the molecular weightof the copolymer (B) being 7 3,100,749 Patented Aug. 13, 1963 l a a t lothers, decyl acrylate, lauryl acrylate, stearyl acrylate, decylmethacrylate lauryl, methacrylate, cetyl metha'crylate, stearylmethacrylate, eicosanylacrylate, docosanyl acrylate and thelike, andmixtures thereof.

In preparing copolymers of type, (A) which have a high nitrogen content(2 .5-3.5%)-and arelatively low molecular weight, the amount ofthevinylpyridine to the acrylate ester used at the start of the reactionshould be about 20-30% vinylpyridine and 80-70% acrylate ester.

1 In preparing copolymers of type (B) which have a low nitrogen content(0.3l%) and a high molecular weight, theratio of vinylpyridine to theacrylate-ester mixture should be about 240% vinylpyridine to,98-90%,acrylate v ester mixture. In the acrylate ester mixture where anester of an acrylic acid and a C alkanol is onecompoalkanol, a mixtureof longchain acrylates can be used. Preferably two or more of these longchain acrylate esters is usedin making the new copolymers. Illustrativeexamples of these esters and mixtures thereof include, among "areemployed in 116101 ratios from 124 tol4:1. Thesuperior in the range101": from 400,000 to 800,000, preferably between 500,000 and 650,000and having a nitrogen contentof from 0.3% to 1%. The two copolymers (A)and (B) should be present in definite'proportionsin which thecopolymer(B) is in a predominant amount. Preferably thecopolymer (A) ,shouldxbepresent in an amount of from 10% to 25% and the copolymer' (B) should bepresentin an amount of from 90% to 75% of the total polymer mixture. Thetwo copolyme'rs, (A) and (B) to about 6% by weight.

' The vinylpyridines used in making the copolymers (A) 01'- (B) maybeexemplifiedtby 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine,.Z-rnethyl-S-yinylpyridine, 4 -methyl- [copolymers is an esterofanacrylic acid and'alower 2-vinylpyridine, S-ethyl-Z-vinylpyridineandQZ-butyl-S- :vinylpyridine, and the like. Particularly preferredgroups comprise 2-, 3-, 4-vinylpyridines L stitu'tedderiyatives'thereof.

helong chain acrylate esters-used ill preparation the copolymer (A vor(l3) include the esters of acrylic alpha-phenyl acrylic acid,alpha-cyclohexyl acrylic acid and the-lower alkyl-subatlids and longchain aliphatic alcohols. Examples of the acrylic acids include acrylicacid and the alpha substituted and chloroacrylic acid. The long chainaliphatic also -hols used inthe esterification of these acids may beexemplified by decyl, lauryl', cetyl, stearyl, eicosanyl, nonadecanyl,and the like alcohols and mixtures thereof. Particularly preferredesters to be used are the acrylic acid' copolymersare obtained whenthehigher ester, 'e.g., those and thelower esters, eeg.thosehavingfromJO to l4 carbon atoms, in the alcohol portion arecombined in a molratiovarying from 1:1to1:3. Y I 1 p The other type ofcomponent used inmaking the 1(B) aliphatic alcohol of notmorethan4jcar-bon atoms. Ex-

amples of these lower acrylates include, among others, i 1 the acrylicacid and methacrylic acid'esters of methanol,

ethanol, butanol, hexanol, isobutyl-alcoholand propanol.

' This other type of component is used-only incertain specific amounts.I It has been found that the ester of the acrylic acids and thealiphatic alcoholcontaining not more than 6 carbon atoms; should beemployed in less than'60 moi percent of the totalofthe acrylate esters.Preferably the lower acrylate, ester is employed in amounts varying from10% i to 30%, by weight ofthe' total of the acrylate molecular weightwithin the desired rangef -Factors polymer {include thefmethiod ofpolymerization" which exert an influence on themoleculanweiglrtof theor-bulk the nature and concentration of the"catalyst employed, thetemperature, andn ature and amount of tlie monomer-s. When thepolymerization is accomplished in solution, the molecular. weight of theproduct willbe lower when the dilution is greater; i.c. ,when theconcentration ofsolvent is greater. Withthe same catalyst,-the

higher polymerization temperature tends to give lower molecular-weights.Polymerization initiators that are particularly suited for use inpreparing the claimed copolymers include various free-radicals yieldingcatalysts as peroxide catalysts, such polymerization in emulsion,suspension, solventsolutmn z ffroin 0.1% to 2% by weight.

.priate solvents. The following ate,' hydnogen peroxide, sodium or'potassium persulfate,

percarbonate,peraoetic acid and the like; Other suitable "catalystsinclude sodium bisu1fite, diethyl sulfoxide, azo

compounds, such as alpha, alpha-ac diisobutylonitrile and initiator adtled Will -vary from 0.1 to 5% by Weight of the material beingpolymerized. Preferred "amounts vary The temperature selected isimportant relative to the ,vi'soosity temperature (VT) propertiesdesired in copolymer s of the ,(B) type. ,For a given lower acrylatecon-"f f ent', the highertemperaturesjgive lower VT values. Preferreclitemperaturesfrange from 40 C. to 160 C. 7 As shown ,in Examples 1 andII temperatures of around dbut temperatures of even up to 126 C. arepreferre 160: C.'may be used.

Theffpolymerization may be conducted in the presence oii absence ofair.In most cases', however, it has been "found desirable to conduct thepolymerization in thelar sence of air, e.g., in the presence of an inertgassuch as nitrogen. Atmospheric, reduced or :superat'mospheric pressuremay be employed. At the end of the polymerization, any unreaoted mono- Imet or monomers'and/or solvents may be removed,

.preferablyby distillation or by precipitation with approancewith theinvention. Unless ,otheiwisespecified, parts di scl o'sed in theexamples are parts by weight. 1

.11; the examples, the molecular- Weights were deter,-

"EXAMPLE 1.:coPoLYMER A TYPE- ,stearyl methacr'ylate were heatedin a50-50 mixture of benzene and a light mineral oil ,(East Texas 100neutral) 7 about 129 C. atwhich time-0.25% Wt. of ditertbutyl I v :roxide was addedand the reaction mixture was main-' ftained at thistemper'ature for about 6 hours. L ght the completionjof the react-ion,the solvent was kstripped iofifand the polymer; diluted with neutralfoil to polymer content-of about 30% by weight and; filtered at 1 09 120.C. p The copolymer had, a molecularrweight of about 200,000t and,;anitrogen content of- 2.94%

EXAMPLE iTL COPOLYM ER 1B TYPE A mixture of 30%; stearly methacrylate-,511% lauryl methacrylate, 14% methyl methacr'ylate-.and 5,.() 2-g methyliwinylpyridinelwasj'charged to a= 300-,gallon stain 7 l e's'ssteelautoclave-, 18 750 50 mixture of benzene and i neutral petroleumoilwasithen addedktothe, autoclave so- 1- part o f the mixture per: 3parts of the total tertbutylperoxide (0.2 5 was then added them ureheated; at 120. 'C-.':for about seven hours.

about3Q% ;by1weight'andfilteredat 10'0-120" Qj 'Ih :p lyni d'a molecularweight of about 600,000 anda 1 n tro c me um- 47- a Qtherflexamples'ofcopolymers (A) and (B)include:

I 'Copo lyr nersA 1 (1) Lauryl methacrylate/2-methyl 5-vinylpyridine,M.W.

like. The amount 'of' the'in-itiator' added may vary over'a considerablerange. "In general, the amount of I H examples illustrate thepreparation of suitziblexpolymers for use inoil compositions in accordbylight scattering method described, in Chem: f Rev vol 40,-p. 319 (1948),and-the ratio of vinylpyridines to allgyl ester wasrdeterminedbyanalysis for nitrogen.

(3) etearyl 'methacrylate/2-vinylpyridine, M.W.

=200,000, percent N:2.8. Y

(4) Stearyl methacrylate/Z-butyl-5-vinylpyridine, M.W.

.(2) Lauryl methacrylate/stearyl methacrylate/methyl methacrylate,M.W.:800,000, percent N=0.6. I

(3) Lauryl methacrylate/stearyl methacr-ylate/butyl methacrylate,M.W."=750,000, percent N=0.5. v (4) Lauryl,methacrylate/stearylmethacrylate/methylmethacrylate/5-ethyl2-viny1-vinylpyridine,' M.W.

('5 Lauryl methacrylateflstearyl r'nethacrylate/ methyl'methacrylate/4-vinylpyridine, M.W.'=60Q,000, percent N='0'.8.

stability and wear inhibition of such ccmpositions'fis' greatly enhancedand the overall pnopertiesof suchcompositions substantially improved byaddition: thereto of butyl-5- methylphenyl) methane; bis 2-liydroxy-3t-butyl-5 in'ethylphenyDethane; v1',1-bis Z-hydroXy-3-t-buty1-5-rneth yl;phenyl)propane; j bis(2-hydroXy-3 -t-butyl-5-r"nethylphenyllbutanegbis(2 hydroxya3 7t-buty1-5-methylphenyl) isobut-ane; 1',1 bis,(6v{hydroxy 5 t butyl -3 meth xylphenyhmethane; bis(2- hydroxy 5 t butyl;3 meth- 3 methylphenyl)propane;. 1,1. bis (2 hydroxy L 5 tamyl 3methylphenyQbutane; "1,1 bis.(-2 hydroxy 5 t amyl 7 3.--methylphenyl)isobutane; etc.

vditert butyl 6. methyl 2,5 ditert butyl 4 -imeth- T heesters ofpentavalent' phosphorus acids suchras-j y I r I 'phenylfdicresyl, aiphenl, "tricrlesyLItrilauryl -andf tr1-' At thej co'mpletion of thereaction,the) benzene was" i ped pfi to final conditions of C. and .10 mm. Hg initrogenfsparging. The benzene-free pr'oductwas.

' then diluted with-neutral pil to ajpolymerfiontentjof stearyl orthQphosphonates; B S terpene r-reaic'tionp" products aridmixture's' thereofare preferred;

. combination of. the 'pyridinecontain'ing copolynier' -miXtures,,fwithor without the added presence of bis- -.pheno ls and/orcertainphos'phor'us compounds, as de fined, imparts properties tohydrocarbons .of ithe luhr icat -ing oil range which make them highlyefiectivein ensuri'ng engine cleanliness,-essentially-nocorrosion and"very: low wear-when they are used forthelubrication of= in 'ternalcombustion engines, and particularly spark ignition i engines which areoperated on fuels which contain metalcontaining substances, such asor'g'anornetallic anti-knock agents, and the like. This co-actionis'ohtained in various hydrocarbon lubricating oils, whether of naturalorigin or A1 h gh the detergency and corrosion inhibition ofvariousiubricants such as mineral oilsare greatly improved" by'additionthereof, of two dissimilar vin'ylpyridine copolymersof groups (A), and(B), the oxidative The 2,4,6-trialkyl phenols containing two tertiaryalkyl 'giohp's in the 2,4; and 2,6-positions -are preferred,-such as2,4-

ltert-butyl-A-methy1olpheriol and- 4, 1

i .kY-libYdo y allgaryl, :aralkyl, -andaryl'phosphites, phosphate xjp eI .phonates, and their thio derivatives, such a s;C g alkyl p sp t s ea.7 d a d r bu y 'z y i .l u y1' a y a y-' clohe'xyl, benzyl, oresyl,phenyl phosphitesjor phosphates, 1 .35 well as ,their 'thio derivatives;-P sg-terpene-reaction product, P S -pine'" oil reaction product'and;.;1net-al' salts thereof such as sodium, potassium, calcium,* oribarium .salts .offP S -terpenereaction product; dibutyl methane.aphosphona'te; dibutyl trichilorornethanephosph'onate, dig butylmfonochloromethanephosphonate, -dibntyl 'chloro benzenephosphonate,"dibutyljr monochlo'romethan'ephom phon-ate, dibut'y-lchlorobenzenephosphonate,andtheilik synthetic, especially oils which aresubstantially parafiinic and/ or naphthenic; they may containsubstantial proportions of hydrocarbons having aromatic characterbut theamounts and types of components should be such that the Dean and Davis(Chem. and Met. Eng, vol. '36, 1929, pp. 618-6 19) viscosity index ofthe base oil is at least. 80, preferably at least 90 to 150. t

The oil may be derived from -a highly paraflinic crude,

, in which case distillation and/ or dewaxing may be sufficient toprovide a suitable base stock; a minimum of chemical or selectivesolvent treatment may be used if desired. Mixed base crudes and evenhighly aromatic crudes which contain paraffinic hydrocarbons alsoprovide suitable oil base stocks by well known refining techniques.Usually these comprise the separation of dstillate fractions of suitableboiling range followed by selective solvent extraction with solventssuch as'furfural,

phenol and the like to provide raffinate fractions which are suitablefor further refining by dewaxing and chemical treatment such as sulfuricacid treatment, etc. Thus, it may be a refined hydrocarbon oil obtainedfrom a paraffinic, naphthenic, asphaltic or mixed base crude,

and/or mixtures thereof,- such as SAE 5W, 10W,20W, 20, 30, 40, 50mineral oils. The hydrocarbon oils may be blends of different mineraloil :distillates and bright stock; they may have blended therewith inminor but com patible proportions fixed oils, such as castor oil, lardoil and the like and/or with synthetic lubricants, such as polymerizedolefins, e.g., polyisobutylene.

The above mixture of low and high nitrogen-containing copolymers, withor without the added presenceof bisphenol and/or an organic phosphoruscompound as defined, when added to a hydrocarbon lubricating oilexhibits a beneficial influence by imparting to the oil or coacting withit so that the final composition has improved oxidationstability,'detergency, corrosion inhibiting and wear-inhibiting propel-ties.Hydrocarbon oils thus improved can be naturalor synthetic oils havinglubricating properties. n g t r i The following non-ash formingcompositions are representative of the invention.

Composition-A:

Example I copolymer Example II co- Percent weight polymer (75%) 5.54,4-methylene bis(2,6-ditertbutyl phenol) 0.5 Trioresyl phosphate .4 0.8Bright stock; 6 Mineral lubricating oil (l0W-30) Balance 1 CompositionB:

Example "I copolymer (25%) Example 11 co polymer (75%) 5 5 CompositionE:

Copolymer A (25% Copolymer B (75%)- 5 In order to demonstrate theutility and improved properties of lubricating compositions of thepresent inven- 6 tion the compositions identified in Table I were testedin the General Motors MS Phase, 2 Test (increased exhaust back pressure)described in AMA Proposed Test Procedure Minutes for MotorOils for ASTMTest Procedure, Boston Meeting, August 1958, using a Cadillac engine andin the Navy Turbine Oil Rust Test (TORT) and the resuits were asfollows:

, to 1%. p 2. The lubricant composition of claim 1 wherein'inr TABLE IGeneral Motors test. i Shaving TORT, Composition i cream percentAvg.liters .Overin lifter rust on rust rating 1 all gallery steel(10=perrust i feet) rating 1 A. 8.1 7.3 None 20 B.-- 8.0 6.8 0 20Mineral oil 1 5% Example 6.4 Coprous-.. 50

I copolymer. Mineral oil 1 5% Example 5.8 5.4 Moderate- 40 II copolymer.Mineral oil 5 p 5 Copleus...

1 Mineral oil-SAE 30.

Lubricating compositions of thisinvention are particularly applicablefor high temperature, high speed use as in aviation engines, automotiveengines and truck engines,

as well as industrial equipment operating under the conditions describedin this invention.

We claim as our invention:

, 1. An improved corrosion resistant and detergent hydrocarbonlubricating oil composition comprising a major amount of hydrocarbonlubricating oil and from 2% to 10% by weight total of a copolymermixture of (A) and (B) of which copolymer (A) comprises 10-25% by weightandcopolymer (B) comprises 9075% by weight of the total polymenmixtureand copolymer (A) isa copolymer of a mixture of 20-30% by Weight. of avinylv.pyridineand 80-70% by Weight of a C1040 alkyl methacrylate havinga molecular weight of 50,000 to 300,000 and a nitrogen content of from2.5 to 3.5% and (B) is a copolymer of a vinylpyridine and a mixture oftwo dissimilar acrylates one being a C 'alkyl methacrylate and the otherbeing a C alkyl methacrylate which constitutes 10-30% by weight of thetotal acrylate mixture, the copolymer having a molecular weight of from400,000 to 800,000 and a nitrogen content of from 0.3

the copolymer B the C alkyl acrylate is a mixture of C1044 alkylmethacrylate and C 4 alkyl methacrylate and the C alkyl methacrylateconstituting 1030% by weight of the totalmethacrylate mixture 3. fAnimproved corrosion resistant and detergent mineral lubricating oilcomposition comprising. a major amount of mineral lubricating oil andfrom. about 2% to about 10% by Weight total of a copolymer mixture of(A) and (B) of which copolymer (A) comprises 10- 25% by weight andcopolymer (B) comprises 9075% vinylpyridine and 80% by weight ofstearylmeth;

. by'weight of the total polymer mixture and copolymer (A) is acopolymer of 20-30% by Weight of 2-rnet hyl5- acrylate. having a'molecularweight of- 100,000200,000

- and a nitrogen content of 2.5-3.5 and copolymer (B) is a copolymer of2-10% by weight of Z-methyl-S-vinylpyridine and a mixture of laurylmethacrylate, stearyl' methacrylate and methyl methacrylate, the methylmethacrylate constituting l0-30% by weight of the total methacrylatemixture, the copolymer having a molecular Tnicresyl phosphate 0.54,4-methylene bis(3,5 ditertbutylphenol) 0.5. Mineral lubricating oilBalance gegigilt7 of 500,000-650,000 and a nitrogen content of 4. Thelubricant composition of claim 3 containing from about 0.01% to about 5%by weight of 4,4-methyl bis(2,6-ditertbutyl phenol).

5. The lubricant composition of claim 3 containing from about .01% toabout 2%, of tricresyl phosphate.

, 7' r 6. The lubricant composition of claim 3 containing a from about0.1% to about 2% by weight of 4,4-methyl bis(2,6- ditertbutyl phenol)and tricresyl phosphate.

7. An improved corrosion resistant and detergent mineral lubricating oilcomposition comprising a major amount of mineral lubricating oil andfrom about 2% to about 10%- by Weight total of a copolymer mixture of(A) and (B) of which copolyrner (A) comprises 10-25% by 'weight andcopolymer (B) comprises 90-75 by .weightof the total polymer mixture andcopolymer (A) is a eop'olymer of 20-30% by Weight of2-rnethyl-5-vinylpyridine and 70-80% by weight of stearyl methac'rylate7 having a molecular Weight of 100,000-200,000 and a. nitrogen contentof,2.5- 3.5% :and/copolymer (B) is a copolymer of 2-10%" by" weight of2-rnethy1-5-vinyl- "pyridinewand a ,mix'tureof lauryl methacrylate,stearyl gr'lethacryl-ate and methyl methacryl-ate, themethyl methacrylate constituting 10-30% by weight of the total meth- V acrylate mixture,the copolymer haying a molecular weight of 500,000-650,000 and anitrogen contentof 0.3 -l%* and from about 0.1% 10.2% by weighteachof'tricresyl phosphate and 4,4"-methylene bis(2,6ditertbutylphenol).

8. The lubricant composition of claim ,7' containing 7 from about 0.1%to about 2% by weight of dicresyl phosphate.

- ReferencesCited the file of this patent rurE STATES PATENTS '2',737,,49,6 ,,C at1in "Man-6, 1956 2,862,976 I Dubbset al'. Dec. 2, 1958v2,889,282 t Lo'rensen et a1. June 2 1959 2,944,086 Coffield'et a1. July5, 1960 ,957,854

Lorensen et a1 Oct. 25, 1960

1. AN IMPROVED CORROSION RESISTANT AND DETERGENT HYDROCARBON LUBRICATINGOIL COMPOSITION COMPRISING A MAJOR AMOUNT OF HYDROCARBON LUBRICATING OILAND FROM 2% TO 10% BY WEIGHT TOTAL OF A COPOLYMER MIXTURE OF (A) AND (B)OF WHICH COPOLYMER (A) COMPRISES 10-75% BY WEIGHT OF THE TOTAL POLYMERMIXTURE AND COPOLYMER (A) IS A COPOLYMER OF A MIXTURE OF 20-30% BYWEIGHT OF A VINYLPYRIDINE AND 80-70% BY WEIGHT OF A C10-20 ALKYL METHACRYLATE HAVING A MOLECULAR WEIGHT OF 50,000 TO 300,000 AND A NITROGENCONTENT OF FROM 2.5% TO 3.5% AND (B) IS A COPOLYMER OF A VINYLPYRIDINEAND A MIXTURE OF TWO DISSIMILAR ACRYLATES ONE BEING A C10-20ALKYLACRYLATE AND THE OTHER BEING A C1-4 ALKYL METHACRYLATE WHICHCONSTITUTES 10-30% BY WEIGHT OF THE TOTAL ACRYLATE MIXTURE, THECOPOLYMER HAVING A MOLECULAR WEIGHT OF FROM 400,000 TO 800,000 AND ANITROGEN CONTENT OF FROM 0.3 TO 1%.